<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<title></title>
	<link rel="stylesheet" href="">
</head>
<body>
<script src='http://cdn.jsdelivr.net/vue/1.0.26/vue.js'></script>
<script src='https://cdn.jsdelivr.net/vue.router/0.7.10/vue-router.min.js'></script>
<div id="root">
<div>
 <ul v-for="(item,index) in listaaa">
  <li v-if='dealFun(item.cdate,index)'>{{item.cdate}}</li>
 </ul>
 </div>
</div>
<script>
var vm = new Vue( {
 name: "",
 data(){
   return {
     listaaa: [{
       cdate: '123'
      },
      {
       cdate: '456'
      },
     ],
     flagName: ''
   }
 },
 methods: {
  dealFun(arg, index) {
   console.log('---------------------------')
   if (arg == this.flagName) {
    return false
   } else {
    this.flagName = arg
    return true
   }
  }
 },
});
</script>
<style scoped>
</style>

</body>
</html>